Priscacara fossils for sale.  Two species of fossil fish Genus Priscacara (Family Priscacaridae) are commonly described from the Green River Formation. 

Priscara liops (Cope1877)  is the most common of the Priscacara genus found in the Green River Formation.  Priscacara liops may be identified by dorsal and anal fin ray counts and the smooth rear margin of the preopercle.  Dorsal fins of liops usually have 9-10 hard spines followed by a fin with 12-13 rays.  Anal fins usually have 3 hard spines followed by a fin with 10-12 rays.

Priscacara serrata (Cope 1877)  is the larger of the two Priscacara species commonly found however the liops species outnumbers the serratas 3 to 1.  Priscacara serrata specimens can be identified by fin ray counts and by the serrated rear margin of the preopercle.  Dorsal fins of serrata usually have 10 spines followed by a fin with 9 or 10 rays.  Anal fins usually have 3 spines followed by a fin with 8 or 9 rays.